EnergyPlus Documentation

EnergyPlus is an open-source whole-building energy simulation program used by engineers, architects, and researchers to model energy consumption and water use in buildings. This site brings together the user guides, application guidance, developer documentation, and API references.

New to EnergyPlus? Begin with the Quick Start Guide or the EnergyPlus Essentials.

Downloads and releases

EnergyPlus is released twice each year, usually in March and September. Formal public releases are recommended for production workflows because development and prerelease versions may introduce input syntax changes that are not supported by the release transition tools.

Download the latest EnergyPlus release or browse all available releases.

Start here

• Quick Start Guide
• EnergyPlus Essentials
• Tips and Tricks for Using EnergyPlus

User guides

• Input Output Reference
• Engineering Reference
• External Interfaces Application Guide
• Output Details and Examples
• Plant Application Guide

APIs and supporting documentation

• EnergyPlus EpJSON Input Schema
• EnergyPlus C API
• EnergyPlus Python API
• Auxiliary Programs Introduction
• EMS Application Guide
• Notices and Acknowledgments

Older documentation

• Getting Started
• Module Developer
• Interface Developer
• Using EnergyPlus for Compliance

Support and project resources

• Visit the EnergyPlus website for program information and resources.

• Ask usage and building-simulation questions on Unmet Hours.

• Request in-depth, developer-supported assistance from the EnergyPlus Helpdesk.

• Consult the developer wiki for development and build information.

Quality, licensing, and contributions

Every EnergyPlus commit and release is exercised by unit, integration, API, and regression tests. EnergyPlus is distributed under a BSD-3-like license and accepts contributions to source code, utilities, tests, documentation, and other project materials. Start with the EnergyPlus contribution policy.

For the repository overview and current development information, see the EnergyPlus project README. On Read the Docs, this link follows the exact source revision used to build the page.

About this documentation

This site combines documentation produced by several tools:

• Sphinx builds the documentation site and Python API reference.

• Doxygen generates the C API reference from the EnergyPlus API headers.

• Pandoc converts the LaTeX user guides into navigable HTML.

Read the Docs publishes two continuously maintained versions:

• latest follows the develop branch.

• stable follows the most recent EnergyPlus release.

For local build instructions, source locations, contribution guidance, and publication details, see the documentation contributor guide. On Read the Docs, this link follows the exact source revision used to build the page.